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Istar 8" F/6

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#1 De Lorme

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Posted 01 August 2014 - 10:07 AM

I'm really excited! Just placed an order through High Point
Scientific for Isatr NEW{REDUCED WEIGHT}8" F/6 Comet Hunter. Mike at Istar said including rings the weight should be around 30lbs with the overall all length at 48".
Should be here in about 4-5 weeks. I'll let you know then
what this brute can show. De Lorme
 

#2 RGM

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Posted 01 August 2014 - 01:42 PM

Looking forward to your review. This is one of the scopes on my list for future purchase.
 

#3 herrointment

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Posted 01 August 2014 - 03:32 PM

That's a major commitment!

That month/month and a half is gonna take forever.....

Looking forward to your report.
 

#4 De Lorme

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Posted 01 August 2014 - 09:40 PM

Yes, But it will give me time to explain to my CR6" that it
no longer meets my needs{LOL LOL} and it has to go{LOL LOL}
It's better that way{LOL LOL}
Really excited! I can't wait to try the NVS7 on it. It's been raining here in the springs like forever I've almost
gotten used to it. But it will pass. Really excited!
De Lorme
 

#5 PowellAstro

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Posted 01 August 2014 - 10:03 PM

What are the specs on this scope? Is it ED glass? It sounds like a great scope. Do you have a link to some info.
 

#6 De Lorme

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Posted 01 August 2014 - 10:24 PM

PowellAstro, This is just a 2 element achro. The way I plan on using it is for DSO I'll put in the NVS7 googles{if needed}. For planets I'll use the Baader 495 Longpass and stop down the lens. Since I've never looked through a triplet or an ED my reasoning is at best guessing but the views I have gotten using the longpass on my CR6" tell me I've got 90% of a 5"ED. So with stopping down the 8" to 6" and then using the 495 Longpass I hope to get the same view
that my CR6" gave me. What do you think? I just couldn't buy a G11 and put cheese on my burrito{LOL}. De Lorme
 

#7 De Lorme

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Posted 01 August 2014 - 10:31 PM

Maybe I could just use the 495 Longpass? Assuming I would be losing about 15% of light that would make it a 6.8" lens
which would give me about a 1/3 more light than my CR6" without the longpass. There's always a trade off some where
unless your hooked to the Federal reserve. De Lorme
 

#8 De Lorme

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Posted 01 August 2014 - 10:44 PM

BTW, The 8079HP I once owned had a very similar wave length as the 495 longpass which is why I didn't use it. So ASSUMING{a mortal sin, LOL}the NVS has a similar wave length I won't be using the longpass on it either.
But I will try it by itself on the 8".
The last time out{a LONG TIME AGO}I was looking at M13 in a very bad sky. I could see it was there but jut no clarity to it. I put in the NVS7 and it was like turning on the light switch. I hope the added aperture will bring better resolution and help with the noise in the NVS7. De Lorme
 

#9 PowellAstro

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Posted 01 August 2014 - 10:54 PM

This sounds good. I think it will do really good! DSOs will be awesome and you can stop it down to 120mm for F/10 on the planets. Cant wait to see some pictures and hear your report!
 

#10 2244champ

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Posted 02 August 2014 - 01:47 AM

Congrats De Lorme, I will also be looking forward to your review. Doug
 

#11 coopman

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Posted 02 August 2014 - 11:55 AM

Wow, that's a BIG'UN. Congratulations.
 

#12 Mike Conley

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Posted 04 August 2014 - 11:40 AM

Look forward to hearing how it performs.
 

#13 De Lorme

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Posted 04 August 2014 - 02:54 PM

In rereading James Edwards review it just excites me how good the views were under a very bad sky.  I haven't seen so much rain here in Colorado springs ever.  Maybe winter will come sooner than expected? I really hope so. While the nvs7 won't go through clouds they will cut through a bad sky.

I would rather use just the eyepiece but if I can't see anything I'll put in the PVS7.  Only 5 more weeks! De Lorme


 

#14 galaxyman

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Posted 06 August 2014 - 08:17 AM

Congratulations De Lorme  :waytogo:

 

It’s an exciting time for you when such an instrument is headed your way.

 

Now you’ll have time to think of what object for “first light”

 

 

Karl
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Edited by galaxyman, 06 August 2014 - 08:18 AM.

 

#15 jrbarnett

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Posted 07 August 2014 - 10:24 PM

I'm really excited! Just placed an order through High Point
Scientific for Isatr NEW{REDUCED WEIGHT}8" F/6 Comet Hunter. Mike at Istar said including rings the weight should be around 30lbs with the overall all length at 48".
Should be here in about 4-5 weeks. I'll let you know then
what this brute can show. De Lorme

Sounds great.  I'm interested in the 8" f/8 or f/12 Asteria of similar design.  Looking forward to your experiences with the speedier version.

 

- Jim


 

#16 Newt_McFracncass

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Posted 07 August 2014 - 10:30 PM

De Lorme,

 

Congratulations on the new scope. I know you once had aspirations of upgrading that 6 inch Synta with R35 glass. I am glad that you have moved on to something leagues above that idea.

 

A big scope like that is usually a harbinger of especially bad weather. 

 

Do you own a wet suit, or a life preserver?

 

Newt D McFracn'cass


 

#17 De Lorme

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Posted 07 August 2014 - 11:46 PM

Newt D MCFracn'cass  It's been raining here or very cloudy for the last month in preparation{paying ahead of time LOL} for my the big 8".

Yes this is way above the CR6" which is a very good{over corrected} telescope.  I'm so glad they got the weight down on the 8" Comet Hunters.

 

Jim, I would have gotten the F/9 but just couldn't swing the G11.  Mike at Istar said the total weight  would be around 30lbs.  I'm confident the

CGEM{it's been good to me} would handle the 8" but I'm going to buy the CGEM-DX just to make sure I have no problems. I've had it 4 years

with only one problem I caused. Celestron so kindly, {didn't see it coming}replaced the motor control board in which I ruined by trying to adjust the

RA and DEC gears for free.  Really excited! Just a few short weeks.

 

De Lorme


 

#18 jrbarnett

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Posted 08 August 2014 - 10:16 AM

Newt D MCFracn'cass  It's been raining here or very cloudy for the last month in preparation{paying ahead of time LOL} for my the big 8".

Yes this is way above the CR6" which is a very good{over corrected} telescope.  I'm so glad they got the weight down on the 8" Comet Hunters.

 

Jim, I would have gotten the F/9 but just couldn't swing the G11.  Mike at Istar said the total weight  would be around 30lbs.  I'm confident the

CGEM{it's been good to me} would handle the 8" but I'm going to buy the CGEM-DX just to make sure I have no problems. I've had it 4 years

with only one problem I caused. Celestron so kindly, {didn't see it coming}replaced the motor control board in which I ruined by trying to adjust the

RA and DEC gears for free.  Really excited! Just a few short weeks.

 

De Lorme

I am leaning CGE Pro if I go 8-inch.  Problem is, the CGE Pro is not a very portable mount.

 

- Jim


 

#19 De Lorme

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Posted 08 August 2014 - 01:30 PM

It's portable if it's inside a roll off roof.  Maybe it's time?   James Edwards comments{on his Istar 8"f/6}about how well the views were in a lot polluted sky

has given me real hope that I won't need the PVS7 but if I should the larger aperture should help reduce the noise.  Just a few more weeks. De Lorme


 

#20 Astronewb

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Posted 08 August 2014 - 10:00 PM

Grats on the purchase, I've been eyeing that beast for a while, especially the new 'lighter' model.   Looking forward to your impressions of color quality of the glass and general fit and finish.  I'm kind of respectful of that aperture after seeing how big a 203mm howitzer bore is while serving for our Uncle.

 

Did you order the white tube model?

 

Regards...Paul


 

#21 chrisastro8

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Posted 08 August 2014 - 10:35 PM

Congratulations and with the rest, I'm very interested in the review of this lighter weight and white version.  Like most mere mortals, an 8" or 7"APO is out of the question so these newer Istar 8" offerings are of great interest...Thanks for posting and congrats again.


 

#22 De Lorme

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Posted 09 August 2014 - 01:46 PM

Paul, I thought they only come in black.  I better talk to Dave at High Point Scientific.  I'm going to buy the CDGEM-DX just to insure I have no problems.

It's the new chip that regulates the power that was the deciding factor.  I just don't see the enormous amount of color that some do.

When using the Baader 495 Longpass I initially see yellow but it just seems t go away after a bit. That's how it is with the PVS when first seeing the green.

It's the noise though that's distracting but then again I can see what I'm actually looking at with pretty good detail in a bad sky.  A good sky has eluded me

so I'm anticipating that the PVS7 will be great when it finally shows up. 

 

chrisastro8, Yes they are expensive but not to bad if payments are spread out over a 3-4 year period.   Istar made a really GREAT decision in

reducing the weight of the Comet Hunters.  I'm quit sure their sales will sky rocket.

 

I've been using the 495 Longpass on my CR6" and just recently discovered that the blue it blocks is just a hair under 10% of the total light.

That would mean the 8" f/6 has 90% of the light coming in making the 8" a 7.625"

Because the blue doesn't interfere any longer views on the moon are really sharp{with the CR6"} and stars are pinpoints of light.

Does any body here know the amount of the Red and yellow that is within the airy disk? 

What I'm trying to determine is at what point does a larger achro equal a smaller ED.

Thanks for straining your brain on this one. LOL,  De Lorme


 

#23 aa6ww

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Posted 13 August 2014 - 04:36 AM

The Good, the Bad and the Ugly, but not in that order, regarding the 204 F/6

The Istar 8" F/6 is not a planetary scope at all. It’s best used under dark skies and at magnifications below 100x to really enjoy what its capable of. It definitely try’s hard on Jupiter for example, but surface sharpness is dulled and contrast is lost and its brighter features are yellowish and cream colored vs white. It produces violent purple skies instead of black skies, just outside of the planets perimeter, further dulling contrast. Saturn isn't as bad, but the results are basically the same. Its a dull experience, regardless of the seeing conditions. Forget Venus, at half phase or less, its just a blob of violet light. You can’t get a tight focuser on Vega, and Sirius, but that usually doesn't mater because who really looks at those stars other than to test your optics, though Sirius does have the pup, which you'll never see with this particular scope. Using an extender or barlow on a scope like this is pointless also.

Stars above Mag 2 in brightness for example, will show a deep purple color. It’s an awkward experience. If you throttle the magnification above 100x to split stars, you need a minus violet filter to keep the stars from being poofy. The filter helps, but remember however, it is a filter, made to attenuate color, which also dulls contrast. 200x, forget it!
If you’re not observing in dark skies with this particular scope, the back ground skies are gray, not black, loosing contrast due to the optical design of this huge doublet with mediocre light baffling. Point the scope 30 degs above a streetlight in a neighborhood, and all you'll get is a washed out bright gray blur in the eyepiece. This is a dark site scope.
The old design is very heavy and very awkward to mount. It's a two person operation to safely mount, not just because of the weight, but awkwardness to hold onto. The new lightweight version will cure the heaviness, but not the awkward handling.

All of these are things you should already know and understand before purchasing any very large fast achromat. No scope is going to perform well under mediocre skies. You seem to be counting on this, it’s not true. At best, a long tube 80mm, 102mm F/15, for example, can tone down clear but turbulent skies, due to its large depth of focus, but no scope is going to be useable through hazy, overcast or cloudy skies. In the article you read, “we” were looking through open holes in the skies, to test its optical characteristics, since it was a first light test, just to see how well the optics were configured. They are excellent.

Understanding the uniqueness of this scope, and what it was designed to do, and you'll be forever happy with it. If you think it’s going to be an 8” planet killer like an APO, or be a superior 8” star splitting monster, then brace yourself for a disappointment.


Having said all of that, if you use the scope as a wide field scope in dark skies, it’s incredible. The skies have to be dark. Not suburban dark, but dark enough that the Milky Way really jumps out at you before it’s even fully dark. Then the scope is a true Monster optically, and will get others annoyed at you because you’re always calling them over to look through your scope.

Point the scope at Andromeda, at the Orion Nebula, at the Pleiades, the veil nebula, the helix, the rosetta nebula, the Trifid, the Omega nebula, and be prepared for an experience you cant get with any reflector or any smaller refractor under dark skies. The stars are very very sharp and pinpoints across the entire field of view when using excellent eyepieces. Multiple galaxies systems, where you need a wider field of view, with these large optics is breathtaking. It’s a totally different visual experience than using a 10" or 12” dob with the same Field of view, or a Meade 10" a C9.25 or C11. None of those are going to give you that visual "Wow" with this much unobstructed aperture, as something like this.

Forum guys will tell you otherwise, but don’t believe it, not for a second, because with out looking through this scope, they are guessing. You can’t deny what this much clear glass will give you, compared to "any mirror" of any size. It’s not like looking through a 6" achomat, just larger, it’s not like looking at a 7" achromat (which I own.)

You can tell who has looked through one of these for nights on end like I have, because they won’t talk about all the nonsense you hear in here, about chromatic aberration, all you will hear about from people who have used this scope, is how spectacular it does what it does well. Ask anyone out here, if in fact they have looked through an Istar 204 f/6 under dark skies, before you take them seriously. If they generalize because they have looked through a 5” or 6” F/6, its pointless, Its not the same.

A car with 450 horse power, and a car with 750 horse power, isn’t the same car. You can generalize and just throw more numbers together in your mind and convince yourself you know what your talking about. Experience speaks for itself.

This much clear glass, is a visual experience you can’t describe. Honestly it isn't. Any 8" refractor is going to make you instantly addicted to this optical experience. It can easily replace and 10" or 11" SCT for its deep space capabilities, not because it sees deeper, because it doesn't, but because of the way it presents the skies to you in the way it gives depth to everything you look at.

I've looked many times through an Istar 204 F/6. It’s a unique scope. It’s a specialized scope. Use it for what it was designed for, and it will be the last large refractor you'll ever lust for. If you want planetary performance or star splitting performance, make an aperture mask on it, and tone the optics down to a 100mm F/12 or a 120 F/10. That’s your planet buster.

If you still want a deep space scope, you'll have to move up to a 14" or larger reflector to feel you've moved further enough away from the unobstructed 8" of glass for dim deep space objects to justify a larger deep space scope.

Istar rolled the dice on these large scopes. They missed the mark I think because of the weight of the original ridiculously heavy tube models. By moving to lighter weight tubes, with these excellent optics, they are going to challenge D&G's market share in a huge way, especially by offering large refractors faster than F/12, something D & G doesn't offer.

They have to be price-conscious about D & G's pricing also. They have to be competitive. If they offer the same light weight scopes D & G offers, with the same superior optics, but at twice the price, their greed will bury them.

Personally, I feel the black tubes are ugly, and white pebble finishes are a cop out compared to a beautiful glossy white tube classic refractor. Others probably don’t care about that. I have a beautiful glossy white tube light weight 180mm TMB designed APM F/6 in a glossy white tube that is as beautiful to look at as it is to look through, and only weights about 25 pounds. Its not an 8” refractor and that extra inch you see in the eyepiece.

The ISTAR 204 F/6 is a big porky refractor. It’s almost caricature big when you look at it. But it will be an experience unlike other on the market, and if you use it the way it was designed and can handle the size, and have an adequate mount, you'll become one of us crazy refractor guys that cant wait for the skies to get dark to get out and use it.

By the way, thats my C14 you see in one of the photos in the article you see posted in here.

...Ralph in Sacramento.

Edited by aa6ww, 13 August 2014 - 04:39 AM.

 

#24 galaxyman

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Posted 13 August 2014 - 11:51 AM

Interesting Ralph your viewpoint is a bit different then Mr. Edward's review.

 

 

 

 

Karl
E.O.H.

 

 

Chesmont Astronomical Society - www.chesmontastro.org
Galaxy Log - http://www.youtube.c...r/GalaxyLog4565
Galaxy Log Blog - http://galaxylog.blogspot.com/
HASB - http://www.haveastellarbirthday.com
Telekit (Swayze optics) 22" F/4.5 Dob
Homemade (Parks Optics) 12.5" F/4.8 Dob
Vixen 5" f/5 reflector (new)
TMB/APM 8" f/9 Refractor”The Beast”. One great DEEP SKY achro
ES 6" f/6.5 achro. Good one
Celestron Omni XLT 102 refractor.
Celestron 10x60mm Binos


Edited by galaxyman, 13 August 2014 - 11:52 AM.

 

#25 De Lorme

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Posted 13 August 2014 - 03:53 PM

Ralph,

 

Any explanation in your mind why yours and James Edwards review are at the opposite end of the spectrum?

 

De Lorme


 






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